1. Field of the Invention
The present invention relates to a vehicle with an auxiliary traveling device.
2. Description of the Related Art
Normal vehicle may run at a high speed higher than or equal to 100 km/h. However, it is typical that the vehicle is not provided a primary power transmission having a power transmission ratio permitting to run at inching speed in the extent lower than 5 km/h when a prime mover for traveling is a high revolution speed and high output.
Accordingly, in case of a vehicle specialized for parade or a working vehicle which is required inching with a traveling prime mover of high revolution speed and high output, a power transmission which has different power transmission ratio other than that of a power transmission of the normal vehicle has to be installed. On the other hand, the vehicle having such power transmission other than the power transmission of the normal vehicle, normally does not have performance for high speed traveling unless it is a special vehicle which has a power transmission with sixteen stages of speed ratio, or so forth. Therefore, such vehicle has to be transported to a destination by a transporter or the like.
On the other hand, the normal vehicle installed with an external power takeoff cannot simultaneously drive the external power takeoff during normal traveling by the primary prime mover or simultaneously drive the vehicle for normal traveling by the primary prime mover while the external power takeoff is in operation, forcedly.
Various working vehicles, such as so-called vacuum type suction cleaner vehicle, may travel to a destination, namely a working site, at high speed similarly to the normal vehicle. However, such working vehicle is not able to run at inching speed required for cleaning operation while predetermined suction cleaning operation is performed using the external power takeoff at the working site.
Accordingly, when it is required to drive the vehicle at inching speed during suction cleaning operation, it is inherent to install a dedicated prime mover separately from the traveling prime mover for using as driving source in suction cleaning operation.
However, in practice, a special vehicle in which is installed a multi-speed power transmission permitting continuous traveling at inching speed in the extent lower than 5 km/h is installed, and also achieving normal high speed traveling performance, with the traveling prime mover of high revolution speed and high output, is quite expensive.
On the other hand, installation of the prime mover dedicated for inching travel, namely the working prime mover separately from the traveling prime mover inherently increase production cost and is disadvantageous in viewpoint of weight and installation space.